1. Field of the Invention
The present invention generally relates to an engine control apparatus. More particularly, the present invention relates to an engine control apparatus for synchronizing a rotational speed of an engine to an input rotational speed of a transmission when a clutch is released and the transmission is shifted.
2. Background Information
In a vehicle equipped with a manual transmission, when a clutch of the vehicle is released in order to shift gears, the input rotational speed of the clutch changes depending on the rotational speed of the engine and the output rotational speed of the clutch, i.e., the input rotational speed of the transmission, changes depending on the vehicle speed and the gear position of the transmission. Consequently, a physical shock (“shift shock”) will occur if the clutch is connected with differing input and output rotational speeds after the gear position of the transmission has been changed.
In order to reduce the shift shock, it is necessary to synchronize the rotational speed of the engine with the input rotational speed of the transmission. In Japanese Laid-open Patent Publication No. 58-200052, when the transmission is shifted, the shift shock is suppressed by executing a rotational speed synchronization control wherewith the rotational speed of the engine is controlled to a rotational speed corresponding to the gear position in which transmission will be set after shifting (post-shift gear position).
In order to reduce the shift shock, it is necessary to synchronize the rotational speed of the engine with the input rotational speed of the transmission. In Japanese Laid-Open Patent Publication No. 58-200052, when the transmission is shifted, the shift shock is suppressed by executing a rotational speed synchronization control wherewith the rotational speed of the engine is controlled to a rotational speed corresponding to the gear position of the transmission after shifting (post-shift gear position). The rotational speed synchronization control is continued until the clutch connects. A clutch pedal switch is provided on the clutch pedal to detect whether the clutch is connected or released.
The clutch pedal switch is a switch that turns “on” when the depression amount of the clutch pedal is larger than a prescribed depression amount. Normally, the prescribed depression amount is a depression amount that is larger than a depression amount corresponding to a disconnect position of the clutch in order to reliably detect if the clutch is released.
However, when the prescribed depression amount is set in this fashion, there is a region where the clutch pedal switch does not turn on even though the clutch is released. In this region, the clutch pedal is not fully depressed, but the clutch is in a released state and it is possible to shift gears. Consequently, it is possible for a driver to shift gears without the rotational speed synchronization control being executed because the clutch pedal switch is not on. In such a case, shift shock will occur.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved engine control apparatus. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.